* i386-tdep.c (regcache_cooked_write_unsigned): Remove define.

(i386_frame_cache): Cache PC.
(i386_frame_pop, i386_frame_pc_unwind): Remove.
(i386_unwind_pc): New function.
(i386_frame_id_unwind): Initialize cache if necessary.  Remove
related assertion.
(i386_frame_register_unwind): Remove FIXME and related assertion.
Add code that fakes a saved processor state with the direction
flag cleared.  Fix unwinding the stack register.
(struct i386_frame_unwind): Remove i386_frame_pop and
i386_frame_pc_unwind.
(i386_gdbarch_init): Set unwind_pc.